XMM-Newton observation of the lockman hole. I. The X-ray data

G. Hasinger*, B. Altieri, M. Arnaud, X. Barcons, J. Bergeron, H. Brunner, M. Dadina, K. Dennerl, P. Ferrando, A. Finoguenov, R. E. Griffiths, Y. Hashimoto, F. A. Jansen, D. H. Lumb, K. O. Mason, S. Mateos, R. G. McMahon, T. Miyaji, F. Paerels, M. J. PageA. F. Ptak, T. P. Sasseen, N. Scharte, G. P. Szokoly, J. Trümper, M. Turner, R. S. Warwick, M. G. Watson

*Corresponding author for this work

Research output: Contribution to journalLetterpeer-review

294 Citations (Scopus)


We report on the first deep X-ray survey with the XMM-Newton observatory during the performance verification phase. The field of the Lockman Hole, one of the best studied sky areas over a very wide range of wavelengths, has been observed. A total of ∼100 ksec good exposure time has been accumulated. Combining the images of the European Photon Imaging Camera (EPIC) detectors we reach a flux limit of 0.31, 1.4 and 2.4 10-15 erg cm-2 s-1, respectively in the 0.5-2, 2-10, and 5-10 keV band. Within an off-axis angle of 10 arcmin we detect 148, 112 and 61 sources, respectively. The log(N)-log(S) relation in the three bands is compared with previous results. In particular in the 5-10 keV band these observations present the deepest X-ray survey ever, about a factor 20 more sensitive than the previous BeppoSAX observations. Using X-ray spectral diagnostics and the set of previously known, spectroscopically identified ROSAT sources in the field, the new sources can be classified. XMM-Newton detects a significant number (∼40%) of X-ray sources with hard, probably intrinsically absorbed X-ray spectra, confirming a prediction of the population synthesis models for the X-ray background.

Original languageEnglish
Pages (from-to)L45-L50
JournalAstronomy and Astrophysics
Issue number1
Publication statusPublished - 2001 Jan
Externally publishedYes


  • Cosmology: diffuse radiation
  • Galaxies: active
  • Galaxies: quasars: general
  • Surveys
  • X-ray: galaxies
  • X-rays: general

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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